Electrical heating apparatus



M. R. MALHOMME.

ELECTRICAL HEATING APPARATUS.

APPLICATION FILED JUNE 30. 1920.

Patented May 17, 1921.

urrsn MA'UEICE RENE MALHOMME, 0F PARIS, FRANCE, ASSIGNOB T0 JACQUES POBEBEJSKY,

0F PARIS, FRANCE.

ELECTRICAL HEATING APPARATUS.

Specification of Letters Patent.

Patented May it, 1921.

T 0 all whom it may concern:

'Be it known that I, MAURICE RENE MAL- HOMME, citizen of the Republic of France, resident of Paris, Seine, France, (post-oflice address 9 Rue Felix Ziem,) have invented a' new anduseful-fElectrical Heating Apparatus, which improvements are fully set forth in the following specification.

The present invention relates to electrical heating apparatus,'and more particularly to apparatus of the type comprising inner and outer elements or members, the former of which is in the nature of a receptacle to contain the substance or material to be heated, and an intermediate resistance element which is connected and arranged to heat the aforesaid inner member or receptacle.

Apparatus of the character indicated are constructed, for the most part, of metal, but are sometimes made of porcelain, glass or other ceramic or vitreous insulating material. The metal implements do not readily lend themselves to decoration, and moreover the can only be cleaned with considerable di culty, so that they are unsuitable for use in medical and chemical laboratories.

Their cost of construction is high, and their consumption of electricity-is excessive.

On the other hand, the porcelain or glass heaters, as heretofore constructed, have likewise proven unsatisfactory, in that they are usually unable to withstand the rises in temperature without cracking. This is due to the fact that the ordinarily comprise two layers or shells 0 ceramic or vitreous mate rial which are in actual or approximate contact with each other and which expand differently under the action of'the heat generated by the interposed resistance element.

It is the object of this invention to provide an improved heater, constructed either partly or wholly of ceramic or vitreous material, which is so designed that a space is formed between both the side walls and the bottom walls of the inner and outer receptacles; such space constituting a dead-air chamber which not only tends to preserve the heat of the inner receptacle and permits the free expansion of the latter, but which also acts to produce, in effect, an air cushion that absorbs the shocks incidental to expansion, thereby avoiding cracking. The outer receptacle may be given any desired shape and may receive any suitable decoration.

An embodiment of the-invention is illustrated in the accompanying drawing, the single figure of-wh ich represents a vertical sectional view of the improved heater.

Referring more particularly to said drawing, A indicates the outer receptacle which, as stated above, may have any desired shape and may be decorated or ornamented in'any desired manner; and B indicates the inner receptacle. The' latter is provided at its top with an out-turned lateral flange B w ic h rests upon the upper edge of the outer receptacle A and by means of which it is suspended therefrom; a layer C of. cement being applied between the said flange and the edge of the outer receptacle to form an hermetic seal orjoint. The inner receptacle is so proportioned with respect to the outer as to leave'an appreciable s ace not only between the' side walls of t e two, but also between their bottoms, as shown; and it is this space, which, of course, is filled with air, that constitutes the dead-air chamber previously mentioned. v

The outer rece tacle A is provided with two contacts D, to which are connected the ends of a resistance wire E. The latter is wound spirally around the inner receptacl B in such a manner as to space its successive turns from one another; and to facilitate the windin and maintain the turns thereof in lace, t e surface of the receptacle may, if esired, be formed with small grooves to receive the wire. The im lement may be completed by the provision o a suitable cover F.

In use, the inner receptacle is filled with the material or substance to be heated, and the resistance element connected with a source of current by means of the contacts D, D, whereupon the heat generated by the passage of the current through the resistance wire will act upon the surface of thesaidreceptacle, with which it" is in Immediate contact, to heat the same.- The implement ma thus be utilized for. heating or even coo ing solid or liquid food, for prepar ng infusions, and for sterilizing purposes etc., and it may also be used for burnnig scent, in which case, however, the cover would have to beperforated.

Itis to be observed that the flange B of the inner receptacle rests upon the up er ed e of 'the outer receptacle, and t at alt ough the cement layer C is interposed I claim as my between these parts, yet the two receptacles are-actually not connected together, the purpose of the cement being merely to form a tight seal or joint. 'lllns is of importance becauseit enables the two receptacles to ex- 7 pand freely, and to difierent extents or in different ways, withoutcdanger of either of them breaking.

Furthermore, it should be noted that the interior space or chamber provided between the receptacles extends not only around the side wall of the inner receptacle, but also beneath its bottom, and that such space or chamber is entirely filled with air, the air tending to preserveits heat and, hence, to kl lrejep the contents of the inner receptacle 1. An electrlc heater, comprising nested inner and ,outerreceptacles of ceramic material, and an interposed resistance element wound around the inner receptacle; said receptacles having an hermetic seal between their upper edges, and the inner receptacle having both its side and its bottom walls spaced from those of the outer receptacle to form a-dead-air chamber which extends entirely around and beneath the said in ner receptacle. I

2. An electric heater, comprising an outer receptacle of ceramic material, an inner receptacle of ceramic material disposed therein and having an out-turned flange at its upper end which rests upon the upper edge of the. outer receptacle, a layer of cement between said fiange and edge to form an hermetic seal between the same, the flange and cement forming the sole support for the inner receptacle and the sole connection between the two receptacles, and a resistance element connected to heat the inner receptacle; said inner receptacle havin both its side and its bottom walls spaced rom those of the outer receptacle to form a dead-air chamber which extends entirely around and beneath the said inner receptacle.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

MAURICE RENE MALI- IOMME. Witnesses:

ALrHoNsE' N rooms, CLEMENT S. EDWARDS. 

